From 8ad651705cbd0ad192398c1513d12c02b3197fa1 Mon Sep 17 00:00:00 2001 From: Daniel De Graaf Date: Fri, 4 Nov 2016 11:35:20 -0400 Subject: [PATCH] xsm: add missing permissions discovered in testing Add two missing allow rules: 1. Device model domain construction uses getvcpucontext, discovered by Andrew Cooper while chasing an unrelated issue. 2. When a domain is destroyed with a device passthrough active, the calls to remove_{irq,ioport,iomem} can be made by the hypervisor itself (which results in an XSM check with the source xen_t). It does not make sense to deny these permissions; no domain should be using xen_t, and forbidding the hypervisor from performing cleanup is not useful. Signed-off-by: Daniel De Graaf Cc: Andrew Cooper Acked-by: Wei Liu Release-acked-by: Wei Liu --- tools/flask/policy/modules/xen.if | 2 +- tools/flask/policy/modules/xen.te | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/flask/policy/modules/xen.if b/tools/flask/policy/modules/xen.if index d83f031df8..eb646f57e9 100644 --- a/tools/flask/policy/modules/xen.if +++ b/tools/flask/policy/modules/xen.if @@ -49,7 +49,7 @@ define(`create_domain_common', ` allow $1 $2:domain { create max_vcpus setdomainmaxmem setaddrsize getdomaininfo hypercall setvcpucontext getscheduler getvcpuinfo getaddrsize getaffinity setaffinity - settime setdomainhandle }; + settime setdomainhandle getvcpucontext }; allow $1 $2:domain2 { set_cpuid settsc setscheduler setclaim set_max_evtchn set_vnumainfo get_vnumainfo cacheflush psr_cmt_op psr_cat_op soft_reset }; diff --git a/tools/flask/policy/modules/xen.te b/tools/flask/policy/modules/xen.te index b52edc24c6..0cff2df1ec 100644 --- a/tools/flask/policy/modules/xen.te +++ b/tools/flask/policy/modules/xen.te @@ -49,6 +49,10 @@ type ioport_t, resource_type; type iomem_t, resource_type; type device_t, resource_type; +# Domain destruction can result in some access checks for actions performed by +# the hypervisor. These should always be allowed. +allow xen_t resource_type : resource { remove_irq remove_ioport remove_iomem }; + ################################################################################ # # Policy constraints -- 2.30.2